Cd spectroscopy

Fluorescence detection was performed using the F-2700 fluorescence spectrophotometer (Hitachi Ltd., Tokyo, Japan). Gel electrophoresis experiments were performed using a Mini-Sub Cell GT System (Bio-Rad Laboratories, Lnc., Hercules, CA, USA). The secondary structure changes of nucleic acids were detected by circular-dichroism (CD) spectroscopy (Applied Photophysics Ltd., Leatherhead, Surrey, UK). The Zeta-Potential image was measured by a Malvern Dynamic Scatterometer (Malvern Instruments Ltd., Enigma Business Park Grovewood Road, Malvern, Worcestershire WR141XZ, UK). Double-stranded DNA was synthesized by a PCR instrument (Biometra, Göttingen, Germany). The amount of binding of the magnetic beads to the nucleic acid was measured by an Evolution 201 UV-Vis spectrophotometer (Thermo Fisher Scientific Co Ltd., Beijing, China)

CD experiments were performed by using CD spectroscopy (Applied photophysics, United Kingdom) to determine the secondary structure of SP1 at 15°C, 25°C, 35°C, 45°C, 55°C in a 1-mm quartz cell. The peptide was dissolved in 50% trifluoroethyl alcohol (TFEA) (Macklin, Shanghai). NaOH or hydrochloric acid were used to adjust pH. CD spectra were acquired using a measurement ranging from 180 to 260 nm, and a 0.5 nm/min scanning speed was used. All measurements were repeated three times. The analysis of the secondary structure content was performed using the CDSSTR method at the DICHROWEB website (59 (link)– (link)61 (link)), and the reference data set SP175 was used to analyze the spectrum data (62 (link)).